This usually happens when WebHarvy is unable to detect the end of pagination. This can be avoided by enabling the Automatically remove duplicate records while mining option in Miner Settings. When this option is enabled, mining is automatically stopped when a page full of duplicate entries is encountered.
This can also be prevented by configuring the next page link by clicking on the direct link to load page number 2 (if present), instead of clicking on the 'next' link. This is as shown in the second image displayed at How to select pagination links ?